Truss-bridge.



Patented July 9, |90I.

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TRUSS BRIDGE.

(Appximnm almaar. 7. 190x.)

2 Sheets-Sheet l.

(No Model.)

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No. 678,239, Patented luly 9, |90I.

, T. G. GILFILLAN.

TBUSS BRIDGE.

'(Applcgtiouled Har. 7, 1901.,

2 Sheets-Sheet 2.

(No Model.)

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UNITED 'STATES PATENTOFFICE.

THOMAS G. GILFILLAN, OF UNION, OREGON, ASSIGNOR OF ONE-HALF TO i SAMUEL A. PURSEL, OF SAME PLACE.

TRUSS-BRIDGE.

SPECIFICATION forming part 0f Letters Patent No. 678,239, dated' July 9, 1901. Applioatlon filed March 7, 1901. Serial No. 50,168. (No model.)

To a/ZZ whom it may concern:

Be it known that I, THOMAS G. GILFILLAN,

a citizen of the United States, residing at Union,in the county of Union and State of Ore-` gon,have invented certain new and useful Im provements in Truss-Bridges; and I do declare the following to be a full, clear, and exact de-4 scription of the invention, such as will enable others skilled in the art to which it apper-l tains to make and use the same.

This invention relates to truss-bridges, and aims to provide a bridge structure which is simple, durable, and efficient and of maximum strength. l

The invention consists of certain novel features of construction and combination of parts, as will be hereinafter described and claimed, and illustrated in the accompanying drawings, in which- Figure 1 is a view in side elevation of a truss-bridge embodying my invention. Fig. 2 is a longitudinal section thereof. Fig. 3 is a cross-section. Figs. 4 and 5 are detail'views showing the overlapping or break-joint arrangement of the oor-planking longitudinally and transversely of the bridge, and Fig. 6 is a detail view showing a construction for reducing the grade at the ends of the bridge.

Referring now more particularly to the drawings, the numeral 1 represents the main chords of the bridge, and 2 represents the arches or bows,which are made up of boards or planks of suitable length and width bent over a form and securely nailed or spiked together at each layer, so that the whole will form one compact mass, the parts being saturated with tar to preserve them from rust and decay. The boards or planks of the arches are so arranged that each layer overlaps or breaks joint with the ones beneath it, thus providing a self-supporting structure of great strength, wherein the parts mutually cooperate and reinforce each other to prevent undue lateral strain and to distribute the load evenly throughout the entire length of the arches. The ends of the arches formed in this manner are notched in their edges to receive metallic straps or stirrups or bolts 3, which secure it to the chords 1 and to the lower course 4 of the flooring of the bridge, wedge-shaped blocks 5 acting in connection with the end transverse sills 6 as braces and supports for the ends of the bridge.

The lower course t of the bridge-flooring is composed of boards or planks arranged one upon the other in a suitable number of layers and nailed, spiked, or otherwise securely connected together. These boards or planks are also arranged to overlap or break joint with each other in two directions, both longitudinally and transversely of the bridge, as shown in Figs. 4 and 5, whereby a self-supporting base of great strength and durability is provided. The parts of the flooring are furthermore saturated with tar or the like to preserve the metal and woodwork from rust and rapid decay. On this course of the flooring the chords l arel laid, and between these chords and upon the lower course 4 is laid the upper course 7 of the flooring, the same consisting of boards extending transversely,so as to form a non-slipping surface for draft-ani mals.

The arches are connected intermediately to the chords by diagonal struts 8 and by braces 9 to the extended ends of the central crossbeam 10. On opposite sides of the beam 10 are other and shorter cross-beams 11, acting in the nature of braces, and said cross-beams 10 and 1l, the flooring 4, chords l, and arches 2 are securely tied and braced by tie-bolts 12, which are so disposed as to distribute the strain effectually on both sides of the center of the bridge.

The grade of the bridge when formed,las it -may be in some cases, too steep for travel may be raised at the ends by laying upon the llooring '7 longitudinal Wedge-blocks 13, supporting an auxiliary flooring 14, as shown in Fig. 6.

Variations in the form, construction, arrangement, and proportions of the parts may be made Without departing from the spirit and scope of the invention.

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

1. In a bridge, the combination of a flooring comprising a lower course formed of layers of boards or planks arranged to overlap or break joint intwo directions,both longitudiu nally and transversely of the bridge, chords IOO mounted thereon, an upper ooring course In testimony whereof I have hereunto set consisting of boards laid transversely between my hand in presence of two subscribing Wit- Io l the chords, arches, and suitable connections nesses. between the parts substantially as set forth.

2. In a bridgea bowed flooring, Wedge- 'HIOMAS G GILFILLAN shaped blocks mounted thereon at the end of Witnesses: the bridge, and a supplemental flooring laid J. R. OLIVER, on said blocks, substantially as set forth. IL R. OLIVER. 

